beta-Hydroxy fatty acid production by ischemic rabbit heart.
beta-Hydroxymyristate, -palmitate, and -stearate were produced by and accumulated in isolated rabbit heart when perfused ischemically for 2-10 min by the nonrecirculating langendorff technique with 0.75 mM palmitate and 0.16 mM albumin. Tissue fractionation into mitochondria and cytosol showed that by 2 min of ischemia 44% of beta-hydroxypalmitate and 38% beta-hydroxystearate was located in the cytosol; this percentage increased to greater than 50% by 5 min of ischemia. Lipid fractionation studies showed that by 10 min these two beta-hydroxy fatty acids were distributed approximately as 60% acylcarnitine, 20% acyl-coenzyme A (CoA), and 20% free fatty acids. All three chemical forms of beta-hydroxypalmitate were found in both the mitochondria and the cytosol. After 10 min of ischemia beta-hydroxypalmitoyl-CoA and beta-hydroxystearoyl-CoA constituted at least 16% of the incremental long-chain acyl-CoA, whereas beta-hydroxypalmitoylcarnitine and b-hydroxystearoylcarnitine constituted 8% of the incremental long-chain acylcarnitine. These data suggests that myocardial beta-hydroxyacyl-CoA oxidation is limited during ischemia. Substrate accumulates and is transferred to the cytosol where it accumulates primarily as beta-hydroxyacylcarnitine.
D000818:Animals; D002331:Carnitine / Q000096:biosynthesis; D003065:Coenzyme A / Q000096:biosynthesis; D003327:Coronary Disease / Q000378:metabolism*; D005230:Fatty Acids, Nonesterified / Q000096:biosynthesis; D006880:Hydroxy Acids / Q000096:biosynthesis*; D008297:Male; D011817:Rabbits; D013347:Subcellular Fractions / Q000378:metabolism; D013997:Time Factors
D005230:Fatty Acids, Nonesterified; D006880:Hydroxy Acids; D002331:Carnitine; D003065:Coenzyme A